Effect of atmospheric $N_2$ gas pressure on the liquid filling of pores has been studied in the Y-Si-Al-O-N system. Presintered agglomerates (20-120㎛ in diameter) of 14 $Si_3N_4$ - 4 Al N - 41 $Al_2$ $O_3$ - 41 $Y_2$ $O_3$ (weight %) composition have been blended with fine powder mixture of 83 $Si_3$ $N_4$ - 5 Al N - 12 $Al_2$ $O_3$ (Z=1). The compacts have been sintered initially at 1780℃ for 1.5h under 1 atm $N_2$ atmosphere in order to create isolated pores at the agglomerate sites. Powder compacts of agglomerate composition have been placed at the top of the sintered specimen and sintered again at 1780℃ for various times under 1, 3, and 5 atm $N_2$. The liquid has been infiltrated into the sintered boy and filled the isolated large pores, producing liquid pockets. The size of the pores filled with liquid increases with the increasing gas pressure. In liquid pockets are observed gas bubbles which subsequently disappear during prolonged resintering treatment. The significance of external gas pressure for pore elimination is discussed.
